Get ready: a spectacular lunar eclipse will occur on Monday 25 March 2024, where Earth aligns between the Sun and the Moon. This will mean our planet's shadow will be cast on our lunar neighbour, causing it to dim.
The event will coincide with the Festival of Colours, an ancient (and joyous!) Hindu festival that welcomes spring and celebrates new beginnings. For places six hours or more behind GMT (further west than Chicago), the eclipse will begin the night before, on 24 March 2024.
But where will the lunar eclipse be visible? What’s the difference between a penumbral and an umbral eclipse? Will the Moon turn red? And what constellation will the Moon be in during the eclipse? Answers to these questions, and more, are below.
If you’re looking forward to clear nights this year, why not plan ahead with our full Moon UK calendar and astronomy for beginners guide?
When will the lunar eclipse occur?
The penumbral lunar eclipse will occur 24-25 March 2024.
For viewers in the UK, the eclipse will happen in the hours before sunrise, and the Moon will be below the horizon when it reaches the maximum extent. From Bristol, the Sun will rise at 6am GMT on 25 March, so the eclipse will happen in the early dawn sky, just before Moonset.
At 6:03am GMT will be when the eclipse reaches its greatest magnitude, while the entire Moon is still above the horizon. The true maximum, at 7:12am, won’t be visible because the Moon will be below the horizon by this time.
At 6:11am GMT the Moon will begin to set, however, the combination of a Moon low on the horizon and the maximum eclipse phase will make the Moon dim before it sets, so it may actually disappear from view.
Eclipse viewers in the US will be better positioned for the eclipse, as the Moon will be above the horizon for the duration of the lunar eclipse.
For Bristol, UK:
- Penumbral eclipse begins: 25 March, 4:53am GMT (visible, Moon above the horizon)
- Maximum eclipse: 25 March, 7:12am GMT (Moon below the horizon)
- Penumbral eclipse ends: 25 March, 9:32am GMT (Moon below the horizon)
For New York City, US:
- Penumbral eclipse begins: 25 March, 00:53am EST (visible, Moon above the horizon)
- Maximum eclipse: 25 March, 3:12am EST (visible, Moon above the horizon)
- Penumbral eclipse ends: 25 March, 5:32am EST (visible, Moon low on the horizon)
For San Francisco, US:
- Penumbral eclipse begins: 24 March, 9:53pm PST* (visible, Moon above the horizon)
- Maximum eclipse: 25 March, 00:12am PST (visible, Moon above the horizon)
- Penumbral eclipse ends: 25 March, 2:32am PST (visible, Moon above the horizon)
* In the US, the clocks changed to daylight-saving time on 10 March. In the UK, the clocks change to BST on 31 March.
- Related: When is the next solar eclipse?
Where will the lunar eclipse be visible?
The lunar eclipse on 25 March will occur over all of the US, South America and Canada, the UK, much of Europe, much of Africa, North and East Asia, western Australia, the Arctic and Antarctica.
For places further west than Chicago, Illinois, the eclipse will begin the night before on 24 March and will be visible until sunrise.
What exactly is a penumbral eclipse?
All objects, when in front of a light source, cast two types of shadow; a dark central part of the shadow, called the umbra, and a lighter, more diffuse part of the shadow around the edge, called the penumbra. This is the same for the Earth when it’s positioned between the Sun and the Moon.
When the Moon passes through Earth’s penumbra during a lunar eclipse, it will experience a partial shading. Penumbral eclipses can be somewhat difficult to see. To us here on Earth, this will appear as an ever-so-subtle dimming of the Moon’s brightness. You’ll still be able to see the Moon, but it will appear a little fainter than usual.
During a full lunar eclipse, when the Moon moves into the Earth’s umbra, the changes are more dramatic as the Moon will turn red. Depending on where the Moon is in Earth’s shadow, this will determine the intensity of the red colour. For example, when the Moon is in the deepest part of Earth’s shadow, the Moon will take on a blood-red appearance, while it will appear to have a light red tint when in partial shadow.
For future lunar inhabitants, if you were standing on the Moon during a lunar eclipse – you would see the Earth block out the Sun – essentially you would see a solar eclipse!
What causes a lunar eclipse?
During a lunar eclipse, the Earth moves in front of the Sun, so that Earth’s shadow falls on the Moon. The Moon is visible to us via reflected sunlight, so during a lunar eclipse, this sunlight is blocked from reflecting off the Moon’s surface.
There are different stages to a lunar eclipse. During a total lunar eclipse, the Moon first passes into the Earth’s penumbra (the more diffuse outer part of the Earth’s shadow). After that, it will move into the darker umbra, before returning to the penumbra on the other side, and finally out of shadow altogether.
During the lunar eclipse on 24-25 March 2024, the Moon will remain in the penumbral shadow and not move into the central umbra.
Which constellation will the Moon be in?
The penumbral eclipse on 24-25 March 2024 will occur when the Moon is in the constellation Virgo. It will appear almost level with Spica, the brightest object in the constellation, but further towards the west.
Will the Moon turn red?
Unfortunately, not. The Moon will not turn red during the lunar eclipse on 24-25 March 2024, as it is not a total lunar eclipse. At best, eagle eyes may spot the Moon appearing slightly darker, but the effect is incredibly subtle, and nowhere near as impressive as during a total lunar eclipse.
So what will we be able to see? Most likely - not a lot:
"Unfortunately, the Full Moon only passes through the outer, fainter shadow of the Earth on this occasion - such penumbral lunar eclipses are completely unnoticeable!" says Dr Darren Baskill of the University of Sussex.
"To see the difference for yourself, place your hand midway between a large light and a surface at night, and you will notice a smaller, fainter penumbral shadow around the darker umbral shadow of your hand," he suggests.
Why do eclipses come in pairs?
You’ll probably have noticed that whenever there is a lunar eclipse, there’s a solar eclipse hot on its heels – or vice versa. Following on from the lunar eclipse on 24-25 March 2024, there is a solar eclipse on 8 April 2024. And it's set to be much more impressive.
This is due to the alignment of the Sun, Earth and Moon and the orbital plane of the Moon.
The Moon’s orbit is tilted by around 5 degrees relative to Earth’s orbit around the Sun. This means the Moon usually passes above, or below, the plane of Earth’s orbit.
However, there are two points where the Moon's orbit intersects Earth's orbital plane. These points are called ‘nodes’.
During an eclipse season, which happens roughly every six months, the Sun, Earth, and Moon align in a way that allows for an eclipse. If the alignment occurs near one of these nodes, we’ll see both a lunar and solar eclipse within a short timeframe. The first eclipse happens when the full Moon passes through Earth's shadow, resulting in a lunar eclipse, then around two weeks later, during the new Moon phase, the Sun, Earth, and Moon are still neatly aligned, and we get a solar eclipse.
When is the next lunar eclipse?
After 25 March 2024, the next lunar eclipse will be a partial eclipse on 18 September 2024. We’ve still got a way to go until the next total lunar eclipse, which will occur in around one year on 14 March 2025.
Like buses, there will be three consecutive total lunar eclipses, with the other two being 7 September 2025 and 3 March 2026.
Here is a list of the upcoming lunar eclipses:
- 25 March 2024: Penumbral
- 18 September 2024: Partial
- 14 March 2025: Total
- 7 September 2025: Total
- 3 March 2026: Total
- 28 August 2026: Partial
- 20 February 2027: Penumbral
- 18 July 2027: Penumbral
- 17 August 2027: Penumbral
- 12 January 2028: Partial
- 6 July 2028: Partial
- 31 December 2028: Total
- 26 June 2029: Total
- 20 December 2029: Total
Viewing tips for the lunar eclipse
Unlike during a solar eclipse, you do not need any special equipment to view a lunar eclipse. There is no risk to your eyes from looking at a full Moon, so it’s quite safe to look at the Moon during a lunar eclipse. This is because the Moon only reflects sunlight – it doesn’t have its own light source – and it doesn’t emit any radiation dangerous to human eyes.
With clear skies, all you need is your eyes – and perhaps a deckchair if you want to make yourself comfortable outside. For UK viewers, the Moon will be low on the horizon as the eclipse occurs in the hour before dawn, so – foliage permitting – you might not even need to step outside and you’ll be able to look through a window.
And of course, the usual rule of avoiding areas with high light pollution applies if you want to maximise visibility.
Where will the comet be in relation to the Moon?
If you've got your sights set on observing the 'Devil Comet' - for those in the US, the start of the lunar eclipse will offer a slight dimming of the full Moon at the same time the comet is above the horizon. It's not much, but an optimist might say it could marginally increase our chances of spotting 12P/Pons–Brooks before it sinks below the horizon.
So where do you look to see the 'Devil Comet'? Under dark skies, look towards the west-northwest horizon as darkness falls. It's visible now through a telescope or binoculars, but visibility will increase as we approach the end of March. There's also the tantalising possibility of it reaching naked-eye visibility towards the end of the month.
From the UK on the night of the penumbral lunar eclipse, 25 March, 12P/Pons–Brooks will be roughly between Jupiter and Mercury on the western horizon soon after sunset. It will gradually descend towards the horizon as the evening goes on, before disappearing from view around 10pm GMT. While the Everest-sized 'Devil' comet is above the horizon, the Moon will be on the other side of the sky.
For New York, the lunar eclipse starts at 00:53am EST, before reaching maximum at 3:12am EST. The comet will sink below the horizon just after 2am in the opposite side of the sky, so the eclipse may offer US viewers a very (very) slight advantage.
About our expert, Dr Darren Baskill
Darren is an outreach officer and lecturer in the department of physics and astronomy at the University of Sussex. He previously lectured at the Royal Observatory Greenwich, where he also initiated the annual Astronomy Photographer of the Year competition.
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